1. Field of the Invention
The invention relates to paving machines and, more particularly, relates to paving machines having hoppers for storing paving materials and having vertically adjustable gates for controlling the discharge of paving materials from the hoppers.
2. Discussion of the Related Art
Machines for paving asphalt or the like are well known and typically include a front storage hopper in which asphalt or other suitable paving materials are stored and which has at least one discharge opening for discharging the paving materials to a spreader and an associated screed. Flow of materials from the discharge opening is controlled by a vertically adjustable gate mechanism positioned at the discharge opening of the hopper. The position of the gate mechanism determines the effective width of the opening and thus the thickness of the materials discharged from the hopper.
The typical gate mechanism of the type described above is incapable of adjusting the gradient of the channels of materials being fed to the spreader. This incapability may prove disadvantageous in many circumstances. For example, the typical paving machine requires the use of two adjacent feeder chains in the hopper to feed materials to the adjacent discharge openings of the hopper. These feeder chains are necessarily spaced from one another by a distance which results in the delivery of materials to the spreader in parallel windrows or channels having a gap formed therebetween. The spreader is often incapable of completely compensating for this gap, thus resulting in a low spot in the center of the mat formed by the machine. This problem could be avoided or at least alleviated by supplying the materials to the spreader in channels which increase in cross section from the outboard to inboard sides, thus weighting the delivery of materials towards the gap formed between the two channels and facilitating the even distribution of materials by the spreader. However, state of the art paving machines are incapable of providing such a weighted delivery. Even if discharge openings and/or the gates of the typical paving machine were modified to weight the flow of materials towards one side or the other of the opening, the thus modified machine still would be incapable of altering this weighting to meet changing operating conditions.